Teenagers who are physically active
in any way are less likely than their TV-watching
peers to smoke, drink or take other health risks,
a new study suggests.

Researchers found that compared with teens
who spent much of their free time in front of
the TV, those who were active often had higher
self-esteem, better grades and were less prone
to risky behavior like taking drugs, smoking,
drinking or having sex.

The findings, based on a national survey of
nearly 12,000 middle and high school students,
are published in the journal Pediatrics.

"Across the board, children who engaged in
any kind of activity were better off than kids
who watched a lot of TV," said study co-author
Dr. Penny Gordon-Larsen of the University of
North Carolina, Chapel Hill.

Other studies have linked certain content of
television programs, such as violence and sex,
to children's behavior. But beyond this issue,
Gordon-Larsen stated, kids who spend hours watching
TV "miss opportunities" to socialize, develop
skills, learn teamwork and have other experiences
that their more active peers benefit from.

That doesn't mean, however, that kids have
to be on the football team. The study found
that "alternative" activities like skating and
skateboarding -- which adults sometimes frown
upon -- were also related to better self-esteem
and less risk-taking.

That skaters were better behaved than TV watchers
might come as a surprise to some adults who
see these teens as a nuisance, according to
Gordon-Larsen. Skateboarding is banned in many
public areas, and some communities oppose building
skating parks.

But if kids who like to skate have nowhere
to do it, "it's a shame," said Gordon-Larsen.

Not only should parents encourage their kids
to engage in the physical activities they enjoy,
she said, but schools and communities should
also do more to create opportunities for children
to be active.

In other findings, teenagers who played sports
with their parents were less likely than TV
lovers to engage in any of the behaviors the
study considered -- from drinking and drug use
to delinquency.

This finding, write the study authors, underscores
the "important role" parents play in their children's
activities, or lack thereof.

Overall, Gordon-Larsen said, the study results
also highlight the fact that exercise is not
only about weight control. "This study makes
clear that there are other benefits as well,"
she said.